taw(ij)-1/3*taw(kk)*deta(ij)=vistur*(dui/dxj+duj/dxi) so 1/3*taw(kk) should be add to the filted pressure, and the modified pressure is: p(filter)+1/3*taw(kk) and need no model?? But how to calculate the "1/3*taw(kk)" directed? Thanks for help!